In recent years non-contact type individual identification systems that employ RFID (Radio Frequency Identification) tags have been focused on for use in systems for managing the entire lifecycle of a product, including all commercial aspects of production of a product, it's distribution and sales. Radio wave type RFID tags that use 2.45 GHz microwaves are noted for the structure that includes an external antenna attached to an IC element that enables communication to be performed over several meters. Presently, construction is ongoing of systems that operate for distribution of mass-produced products as well as their product management and production history management.
Current examples of radio wave type RFID tag systems using microwaves include products developed by Hitachi or Renesas that use a TCP (Tape Carrier Package) inlet. The production of the TCP type inlet employs the TAB (Tape Automated Bonding) method in which IC elements having all external electrodes formed on the same surface thereof are mounted, each individually, on a tape carrier formed of a polymide substrate with a succession of copper antenna circuits (Kayama Susumu and Naruse Kunihiko “VLSI Packaging Technology”, first and second volumes, Nikkei B P, 1993). RFID tag production processes employing a typical TAB method will now be described with reference to FIG. 1.
As shown in FIG. 1 (a), after IC elements 110 having a gold bump 104 formed on the circuit surface and in which all external electrodes are formed on the same surface are made individual by a dicing process, these are sucked from a dicing film 10 using a vacuum suction unit 20. Next, as shown in FIG. 1 (b), the pieces are moved to a vacuum suction station 30 so that the gold bumps 104 of the IC elements 110 having all external electrodes formed on the same surface thereof are made the surface. Next, as shown in FIG. 1 (c) the vacuum suction station 30 is inverted such that the gold bumps 104 become the lower face. Next, the IC elements 110 having all of the external electrodes thereof formed on the same surface are positioned in the determined position with respect to an antenna substrate 500, made by processing a polymide base with copper foil attached, and thereafter the IC elements 110 are secured in place by a thermal compression binding process using a heater 40. Connections can then be formed at the connecting parts of the gold bumps on an antenna circuit 501 by a tin-gold alloy formed by applying a tin or solder plating thereto. As shown in FIG. 1 (d), the gaps occurring between the IC elements 110 having all external electrodes formed on the same surface thereof and the antenna substrate 500 are sealed using a thermal hardenable resin 600. The condition once the hardening process of the thermal hardenable resin is complete is the intermediate condition of the RFID tag referred to as an inlet. Accommodating this inlet in a label or thin case enables it to be used as an RFID tag.
Other inlet structures include for example having IC chips in which the external electrodes of the IC chip are formed individually on the respective surfaces of a pair of facing surfaces, as developed by Usami of Hitachi, having a glass diode package structure in which a dipole antenna connects to each external electrode formed on the respective surfaces (Japanese Patent Application Laid-Open No. 2002-269520). Further, in the device disclosed by Usami et al, when the IC chip in which the above described two external electrodes are formed individually on each of the surfaces of a pair of facing surfaces of the IC chip are furnished with an oscillation slit type dipole antenna, the external electrodes formed individually on each of the surfaces of a pair of facing surfaces of the IC chip are disposed between antennae to produce a sandwich antenna construction (ISSCC Digest of Technical Papers pages 398-399, 2003). In this dipole antenna structure having an oscillation slit, the impedance of the antenna and input impedance of the IC chip can be made compatible by changing the width and length of the slit, thereby increasing the distance of achievable transmission.
In order to realize distribution and product management of a large number of products by a non-contact type individual identification system using RFID tags it is necessary to attach an RFID tag to each product, and this makes mass production of RFID tags cheaply indispensable.
However, in order to form a resonant circuit in which the two external electrodes of IC chips are connected to an antenna by spanning an oscillation slit in an oscillation type dipole antenna construction that provides favorable communication properties, it is necessary, in the case of IC chips in which all the external electrodes are formed on the same surface, to achieve precise positioning of the two external electrodes for signal input and the slit. Therefore, in the TAB method shown in FIG. 1 of the conventional art, the steps involved include suction from the dicing film applied to IC chips having all external electrodes formed on the same surface thereof and conveyance using a vacuum suction device, or positionally aligning and arranging IC chips having all external electrodes formed on the same surface with an antenna substrate, and further, performing thermal compression binding of the IC chips having all external electrodes formed on the same surface thereof to an antenna substrate, before sealing with resin is performed for each individual IC chip. In these processes, it is extremely troublesome to make the operating time for each step occur in one second or to reduce this below one second. This is a substantial problem affecting mass production in this method and thus the TAB method has significant problems.
Further, if the available operating time is long then labor expenses increase concomitantly, mitigating against lower-cost production. Also as the connection between IC chips having all external electrodes formed on the same surface thereof and an antenna substrate is realized using a gold-tin or gold solder connection, it is necessary to use as the substrate material, a taped substrate having copper foil attached to polymide film, which is expensive but strongly resistant to heat. This makes it very difficult to produce the inlet economically.
If the above described sandwich antenna construction is used, which encloses by an antenna each of the external electrodes formed individually on each of the surfaces of IC elements formed having two external electrodes each disposed individually on the respective surfaces that are a facing pair, when employing the production method of the conventional art that uses the TAB method in which it is not necessary to achieve precise positioning between an oscillation slit and each of the external electrodes formed individually on each of the surfaces of the IC elements, the production method incorporates processes to reduce the available operating time in which a plurality of the chips undergo suction and conveyance simultaneously using a plurality of vacuum suction devices. This creates problems however as complex production equipment is required which increases equipment investment costs, and it is difficult to perform mass production of the inlets at low cost.
Here, a method has been devised (refer Japanese Patent Application No. 2004-008313) in which the above-mentioned conveyance of the IC chips involves having a disc-like conveyor that provides a plurality of notches disposed on the outer periphery thereof, each of which can accommodate the insertion of one of the IC chips, having each of the IC chips accommodated by each of these notches and then rotating the disc-like conveyor so that a plurality of the IC chips the maximum number of which corresponds to the number of notches, can be simultaneously conveyed.
There are problems confronting this method that employs a disc-like conveyor however. When the IC chips are inserted into the notches the chips can become stuck to the notches, or the IC chips can become sandwiched between the disc-like conveyor and the base that supports that mechanism for example, preventing the equipment from running smoothly.